Gate valve

ABSTRACT

A sliding gate valve has an improved seal and a cammed gate that cooperate to provide better sealing, along with easier operation and a gate of lighter construction. The improved seal is a flexible annular lip around the valve passageway having a ridge engaged by the gate and surfaces on opposite sides of the ridge inclined upward away from the gate for easy camming of the gate into engagement with either side of the ridge. The cammed gate includes cam followers on the gate and cams in the valve housing for forcing the gate against the seal as the gate nears its closed position.

ilite tates ate Townsend 1 1 Mar. 27, 1973 1 1 GATE VALVE abandoned.

[52] U.S.-Cl. ..25l/203, 251/172, 251/328 [51] Int. Cl ..Fl6k 25/00 [58]Field of Search ..277/205, 206; 251/172, 203

[56] References Cited UNITED STATES PATENTS 3,207,524 9/1965 Trhovich..277/206 3,258,244 6/1966 Hilton ......251 203 3,333,814 8/1967 Sargent..2s1/172 x 3,378,269 4/1968 Castor ..277/205 3,384,382 5/1968 Rink....277/205 X 3,458,220 7/1969 Rose ..277/206 X Primary Examiner-HaroldW. Weakley AttorneyCumpston, Shaw & Stephens [57] ABSTRACT A slidinggate valve has an improved seal and a cammed gate that cooperate toprovide better sealing, along with easier operation and a gate oflighter construction. The improved seal is a flexible annular lip aroundthe valve passageway having a ridge engaged by the gate and surfaces onopposite sides of the ridge inclined upward away from the gate for easycamming of the gate into engagement with either side of the ridge. Thecammed gate includes cam followers on the gate and earns in the valvehousing for forcing the gate against the seal as the gate nears itsclosed position.

3 Claims, 10 Drawing Figures atented March 27, 1973 3,722,857

4 Sheets-Sheet 1 INVENTOR. CHARLES L. TOWNSEND HIS ATTORNEY PatentedMarch 27, 1973 3,722,857

4 Sheets-Sheet 2 INVENTOR. CHARLES L. TOWNSEND HIS ATTOR/VE' Y atenfied27, 1973 4 Sheets-Sheet 5 I NVE NTOR CHARL ES L. TOWNSEND PatenfledMarch 27, 1973 3,722,857

4 Sheets-Sheet 4 Haw.

INVENTOR. CHARL 58 L. TOWNSEND HIS ATTORNEY GATE VALVE This is acontinuation of application Ser. No. 828,396, filed May 27, I969 and nowabandoned.

THE INVENTIVE IMPROVEMENT ing with low operating forces, and has a longseal life.

The inventive combination allows a gate of lighter construction, a valvethat is easier to operate and that does not stick, jam, or leak.Furthermore, these advantages are achieved without extra expense inmanufacture or installation, and without any sacrifice in simplicity,reliability or durability.

SUMMARY OF THE INVENTION The improved seal for a sliding gate valveincludes an annular lip arranged around the valve passageway with theproximal end of the lip secured to the valve housing and the distal endof the lip extending flexibly and generally horizontally inward aroundthe periphery of the valve passageway so that the distal end of the lipis movable axially of the passageway. The gate side of the lip has aridge confronting the gate between the distal and proximal ends of thelip, and the surfaces of the lip on opposite sides of the ridge areinclined away from the gate at acute angles in the normally assumedposition of the lip. The lip is thickest in the region of its ri ge, andhas substantially equal and uniform thickness on opposite sides of theridge.

The cammed gate has a plurality of cam followers arranged on the side ofthe gate opposite the seal, with the housing on that side of the gatehaving a corresponding plurality of cams outside the valve passagewayand arranged so that cams and cam followers move the gate axially of thepassageway against the seal as the gate nears its closed position toforce the gate against the seal for sealing the passageway closed.

The inclined surfaces of the lip adjacent the ridge facilitate cammingof the gate against the ridge as the gate is slid against the seal, andthe inclinations on each side of the ridge ensure that such camming issuccessful at both the near and far sides of the seal as the gate slidesacross the seal. Camming of the gate against the seal is particularlysuccessful with the inventive seal and allows the gate to be made oflighter construction and to move freely and easily across the seal andyet make an effective and reliable sealing engagement with the seal,without excessive wear.

DRAWINGS FIG. 1 is a plan view of the preferred embodiment of theinventive sliding gate valve showing the valve in closed position;

FIG. 2 is a side elevational view of the valve of FIG.

FIG. 3 is a cross section of the valve of FIG. 2 taken along the line3--3 thereof;

FIG. 4 is a cross section view of the valve of FIG. 1 taken along theline 4-4 thereof;

FIG. 5 is a cross section view corresponding to FIG. 4 but showing thevalve in open position.

FIG. 6 is a cross section view of the valve of FIG. 5 taken along theline 6-6 thereof;

FIG. 7 is a cross section view of the valve of FIG. 6 taken along theline 7-7 thereof;

FIG. 8 is a cross section view corresponding to FIG. 7 but showing thevalve in closed position;

FIG. 9 is a cross section view corresponding to the view of FIG. 6 butshowing the valve in closed position;

FIG. 10 is an enlarged fragment of a cross sectional view correspondingto the views of FIGS. 4 and 5, and showing the valve in both open andclosed position.

DETAILED DESCRIPTION For convenience, all the views of the drawing showvarious aspects of a single preferred embodiment of the inventive valve.Corresponding parts have the same reference numbers throughout thedrawings. It should be understood in following this description, thatother embodiments and variations are possible within the spirit of theinvention.

Valve 10 is designed for use in the sewage storage systems of boats,travel trailers, camp trailers, etc., but it is not limited to theseapplications. Generally, valve 10 has a housing including a slide body11 and a cover 12 extending around a valve passageway 13 through thehousing. A gate 14 slides transversely of passageway 13 in slide body 11under cover 12 to open or close passageway 13. Gate 14 is moved by rod15 having a handle 16, and a spring latch 17 is arranged for clampinghandle 16 in place to hold gate 14 in a closed position. A pipeconnection 18 is shown bolted to the housing of valve 10 to afford anentrance to passageway 13. Valve 10 is installed in place asdesir'ed inany generally known way to be opened and closed by gate 14.

SEAL

Cover 12 has annular channel 20 around the periphery of passageway 13above gate 14. A seal generally denoted as 21 is disposed in channel 20for a sealing engagement with gate 14. A base portion 22 of seal 21 ispreferably molded in place inside channel 20 to secure seal 21 inposition around passageway 13. The sealing portion of seal 21 is aflexible lip 23 having its proximal end 24 joined to base 22, to anchorit to channel 20 in the housing of valve 10. Lip 23 extends generallyhorizontally inward around the periphery of passageway 13 in itsnormally assumed position as best shown in FIG. 10. The distal end 25 oflip 23 is thus resiliently disposed to move axially of passageway 13.

The under side of lip 23 has a ridge 26 confronting gate 14 andextending downward between proximal end 24 and distal end 25. Undersurfaces 27 and 28 of lip 23 adjacent ridge 26 incline upwardly awayfrom gate 14 at acute angles to gate 14. Lip 23 is thickest in theregion of ridge 26, and has a substantially uniform and even thicknesson opposite sides of ridge 26.

Gate 14 has a bevel 29 at its upper forward edge to interact withsurfaces 27 and 28 of the under side of lip 23. As gate 14 slides underseal 21, bevel 29 first engages incline surface 28 of seal 21 to cam lip23 upward smoothly as gate 14 advances. After gate 14 has passedhalf-way under seal 21, bevel 29 begins to engage surface 27 around theinner bottom of lip 23 for camming the remainder of lip 23 upward asgate 14 proceeds toward its closed position. This ensures a smoothcamming of lip 23 upward on both sides of ridge 26 as gate 14 slidesacross each half of seal 21. The result is a smooth action requiringrelatively little force and resulting in a good resilient seal betweenlip 23 and gate CAMMED GATE Gate 14 is preferably cammed into its closedposition in engagement with seal 21. For this purpose a pairof forwardcam followers 30 and a pair of after cam followers 31 extend downwardfrom the under surface of gate 14 to form slide projections. Camfollowers 30 ride in grooves 32, and cam followers 31 ride in grooves 33formed in slide body 11 of the housing of valve 10. Grooves 32 and 33have respective cam ramps 34 and 35 at one end leading to the ungroovedplane surface 36 of slide body 11, and cams 30 and 31 riderespectivelyup ramps 34 and 35 to surface 36 as gate 14 nears its closed position.This moves gate 14 axially of passageway 13 and against seal 21.

The camming of gate 14 against seal 21 as it nears a closed positionensures better compression of seal 21 and a more secure sealingengagement with seal 21. It also allows gate 14 to be made of fairlylight construction, and strengthening ridges previously found necessaryon the under side of gate 14 can be eliminated. Gate 14 moves relativelyfreely and easily under seal 21 without having to compress seal 21 fullyuntil it nears its closed position, and this contributes to smoothaction without requiring undue force. It also reduces the wear on seal21 and contributes to long and reliable sealing.

COMBINATION OPERATION The improved seal and the cammed gate cooperate inthe inventive valve to provide an especially advantageous sealingarrangement. Seal 21 with it's axially movable lip 23 is especiallydesigned for cooperating with a cammed gate that also has a scope ofaxial movement. Cam surfaces 27 and 28 on the bottom of seal lip 23cooperate with the advancing gate for a slight camming of seal 21axially of passageway 13, and when gate 14 is cammed toward seal 21 tothe closed position best shown in FIG. the whole under surface 28 of lip23 adjacent ridge 26 is brought into the plane of the top of gate 14 fora broad and secure sealing engagement with gate 14. Without the axialcamming of gate 14, surface 28 could not be readily made to flexsufficiently to bring surface 28 flat against the upper surface of gate14. If lip 23 were flexed its full extend by the closure of an uncammedgate, the friction forces would besubstantial, and gate 14 wouldmovestiffly and require considerable force. Also, gate 14 would have to bemade of stronger construction to accomplish such flexure, and the sealwould suffere excessive wear. Hence, in cooperation, cammed gate 14 andseal 21, with its widely flexible lip 23 having inclined undersu rfaces27 and 28, accomplish improved sealing in sliding gate valves of thistype.

Persons wishing to practice the invention should remember that otherembodiments and variations can be adapted to particular circumstances.Even though one point of view is necessarily chosen in describing andclaiming the invention, this should not inhibit broader or relatedapplications within the spirit of the invention. For example, differentcamming arrangement can be used to cam the gate towards its closedposition, housing and passageway parts can have a variety of shapes andsizes, and the inventive seal can be anchored in place in a variety ofways to function within the spirit of the invention.

I claim:

1. In a sliding gate valve having a housing around a verticalpassageway, a horizontally sliding gate for opening and closing saidpassageway, and a seal engaged by said gate for sealing said passagewayclosed, an improved sealing arrangement comprising:

a. said seal having an annular, flexible lip, arranged around saidpassageway;

b. a proximal end of said lip secured to said housing;

c. said lip being self-supporting to extend flexibly and generallyhorizontally and radially inward around the perimeter of said passagewayso that the distal end of said lip is movable vertically axially of saidpassageway;

d. the under side of said lip having a ridge confronting said gate andforming the lowermost surface of said lip;

said ridge being formed between said distal and said proximal ends ofsaid lip;

f. each of the surfaces of said under side of said lip on opposite sidesof said ridge being inclined downward toward said gate at acute anglesto the horizontal in the normally assumed position of said lip, saidunder surfaces meeting at said ridge and forming inclines tending tomove up over the leading edge of said gate as said gate slides closedunder said annular lipv to lift said ridge during any portion of theclosing'motion of said gate;

. said lip being thickest in the region of said ridge and havingsubstantially equal and uniform thickness on opposite sides of saidridge;

. said housing being configured to provide a plurality of cams outsidesaid passageway;

. said gate being configured to provide a plurality of cam followers;

j. said cams and said cam followers being disposed for raising said gateaxially of said passageway against said ridge to lift said lip as saidgate nears its closed position and press said ridge and said gatetightly together to form a seal around said passageway; and

it. said housing includes a slide body configured to provide groovesextending in the direction of sliding motion of said gate, with saidcams comprising ramps in the region of the ends of said grooves.

2'. The gate valve sealing arrangement of claim 1 wherein said followerscomprise glide projections arranged for slidingin said grooves, and saidhousing includes a cover arranged over the seal side of said gate andextendingaround said passageway.

3. The gate valve sealing arrangement of claim 2 wherein said cover isformed with an annular channel around said. passageway and said proximalend of said lip is formed as a bodymolded into said channel.

I I t i i

1. In a sliding gate valve having a housing around a verticalpassageway, a horizontally sliding gate for opening and closing saidpassageway, and a seal engaged by said gate for sealing said passagewayclosed, an improved sealing arrangement comprising: a. said seal havingan annular, flexible lip, arranged around said passageway; b. a proximalend of said lip secured to said housing; c. said lip beingself-supporting to extend flexibly and generally horizontally andradially inward around the perimeter of said passageway so that thedistal end of said lip is movable vertically axially of said passageway;d. the under side of said lip having a ridge confronting said gate andForming the lowermost surface of said lip; e. said ridge being formedbetween said distal and said proximal ends of said lip; f. each of thesurfaces of said under side of said lip on opposite sides of said ridgebeing inclined downward toward said gate at acute angles to thehorizontal in the normally assumed position of said lip, said undersurfaces meeting at said ridge and forming inclines tending to move upover the leading edge of said gate as said gate slides closed under saidannular lip to lift said ridge during any portion of the closing motionof said gate; g. said lip being thickest in the region of said ridge andhaving substantially equal and uniform thickness on opposite sides ofsaid ridge; h. said housing being configured to provide a plurality ofcams outside said passageway; i. said gate being configured to provide aplurality of cam followers; j. said cams and said cam followers beingdisposed for raising said gate axially of said passageway against saidridge to lift said lip as said gate nears its closed position and presssaid ridge and said gate tightly together to form a seal around saidpassageway; and k. said housing includes a slide body configured toprovide grooves extending in the direction of sliding motion of saidgate, with said cams comprising ramps in the region of the ends of saidgrooves.
 2. The gate valve sealing arrangement of claim 1 wherein saidfollowers comprise glide projections arranged for sliding in saidgrooves, and said housing includes a cover arranged over the seal sideof said gate and extending around said passageway.
 3. The gate valvesealing arrangement of claim 2 wherein said cover is formed with anannular channel around said passageway and said proximal end of said lipis formed as a body molded into said channel.